FR2683749A1 - DEVICE FOR OPTIMIZATION BY SIMULATION OF THE APPLICATION OF A FLAN IN SHEET AGAINST THE MATRIX OF A TOOL OF BINDING. - Google Patents

Abstract

The invention relates to a device for an optimization by simulation of the application of a sheet blank against the die of a stamping tool. On a base (7) oriented horizontally, several supports (8) can freely move by translation, rotate around a vertical axis and be fixed on the base (7) in any translational position or any angular position; each support (8) carries a clamp-shaped clamping bracket (10) which can, by means of corresponding bearings rotate, and be fixed, around two mutually orthogonal axes (11, 12) and which can, by means of 'a vertical guide (13), be adjusted and fixed in height on the corresponding support (8); each clamp (10) has on the lower side a partial bearing surface (14), through which a partial area of an application surface of the blank (5) can be simulated, and it has on the upper side a clamping jaw (15).

Description

The present invention relates to a device for optimization, for

simulation of the application of a

  sheet blank against the die of a stamping tool.

  The stamping of body parts in stamping presses can be divided into four phases, including: placing the blank, closing the blank holder and applying the clamping force, lowering the punch in the stamping process neatly said, and

  Opening the tool and removing the stamped part.

  Outside the stamping process

  said, and which has been described very frequently in the literature.

  the other two previous phases also have an influence on the partial quality

  stamping machine With good stamping tools

  bottom, the lower die and the blank holder, whose shape is adapted in correspondence, must be arranged in such a way that, after placing the blank on the lower die, the blank can be applied by the blank holder without folds over the entire bearing surface of the lower die In this respect, it must be taken into account that the bearing surface of the die is generally not flat but is already roughly approximating the spatial contour profile of the piece Finally, the blank pressed between the blank holder and the die must be maintained spatially with a shape such that the point of first contact of the stamping punch with the blank is situated approximately in the middle of the blank. In the art earlier, an attempt was made to obtain a usable form of the surface of application of the matrix or blank-holder in

  experimental tools consisting of a fashion material

  It can be loaded sufficiently, but nevertheless easy to implement, such as for example plaster, a synthetic resin or combinations of wood and plastics, operating by a long and expensive iteration process in accordance with the method. trial and error "Another difficulty arises from the fact that the blank tight in this way on the edge can absolutely not be observed any more and that any wrinkles can only be detected after the opening of the experimental tool. conclusions of the shape and position of the folds and modify with great experience the matrix and the blank holder to try a new tightening of the edge of the blank The experimental tool corresponds each time to a stamped part specific to the 1: 1 scale and, after completion of the tests concerning the matrix and the blank holder corresponding specifically to the stamped part, it is used in its condition for the realization of the stamping tool for production After that, for the production of a

  vehicle bodywork, a great many tools for

  different headstocks have been designed and

  it is necessary to devote, for the design of the

  many different matrices, a lot of time

  must be planned before the start of production.

  An object of the invention is to make available

  an auxiliary means which makes it possible to design matrices or blanks of this kind, intended

  specifically to parts stamped optimally

  male for the form, in a shorter time and with

reduced fees.

  This problem is solved according to the invention

  by means of a device for an optimization, by simula-

  the application of a sheet blank against the matrix

  of a stamping tool, characterized in that it comprises

  takes the following components, having the features indicated in the following: a flat base, oriented horizontally and whose length and width are respectively greater than those of the largest blank to implement, several supports, freely movable on the base, rotatable about a vertical axis and capable of being fixed in any translation position or angular position on the base, each support having a clamping bracket in

  form of clamp, which can, by means of corresponding bearings

  to be moved by pivoting, and fixed, around

  two horizontal and perpendicular pivot axes

  between them, and which can, by means of a vertical guide being able to be immobilized, be adjusted and fixed in height on the support, each clamping caliper comprising on the lower inner surface of the opening

  clamp, a partial support surface, which constitutes

  kills a partial area of a simulated

  1 for the sheet blank, and opposite the partial support surface provided in the clamp opening a clamping jaw, movable parallel and perpendicularly

  to the supporting partial surface and which can be

  with a definite force against the surface

support.

  Thanks to a large number of clamps mounted in an adjustable way on stable supports, the die and the blank holder can be simulated zone by zone and can be modified in a simple and fast way; in addition, the blank tight on the edge is cleared to the sight permanently so that it is

  possible to directly observe the formation of folds

  This is possible to modify the shape of the edge locking part when the blank is tightened, so that

  the effect of changes of shape of the part of serra-

  Edge clearance on possible wrinkles can also be observed directly The optimal shape of the edge clamping part can thus be found quickly

  also without sample clamping operation.

  To be able to check if the stamping punch actually comes into contact with the

  middle of the blank tight, just a movement of descending

  locally defined part of the stamping punch

  weaving or a model of the final piece The position

  the first point of contact can be detected visually

  by lateral observation and it is also possible

  to define it by setting up registration marks.

  According to other features of the device according to the invention:

  The vertical guide, which can be adjusted and fixed in

  carrier, is arranged as a guide provided with

  two guide columns, parallel and vertically oriented

  calmly, as well as a cart guided on them.

  Among the two bearings of the clamp, which are horizontal and can pivot about two mutually orthogonal axes, one of the bearings is constituted firstly by at least one guide sleeve, horizontal and arranged in or on the carriage, and on the other hand by a guide pin extending rearward to

from the clamping bracket.

  The other of the two horizontal bearings is constituted by a hinge, arranged between the trunnion of

  guiding and clamping bracket and can pivot uni-

  dimensionally. The actuating member is arranged as a hydraulic piston for applying with a defined force the clamping jaw of the clamping bracket against the

partial support surface.

  The support, freely mobile on the base and able to

  turn and also be fixed, is guided in its movement

  on the base by means of guide rollers

  be stopped and / or retracted completely.

  The vertically guided carrier can be moved precisely by means of a flywheel and a fine-threaded spindle and can be fixed automatically by means of the irreversibility of the fine-threaded spindle.

  The guiding pin and / or the articulation of the

  clamping means can respectively, by means of a flywheel and by means of a fine-threaded spindle, supported for its pivoting movement, which is articulated by means of a lever on the spindle of

  guide or the clamp and which is oriented tangen-

  relative to the pivot axis corresponding to

  be moved accurately and automatically

  fixed by the irreversibility of the spindle

with fine thread.

  The partial bearing surface, disposed at the bottom in the gripper opening, is located on a piece of form, which can be put in place in a replaceable manner and in

  a defined position in the lower part of the

  the clamping jaw, located opposite the partial bearing surface, is also provided with a shaped part, exchangeable and can be installed on it in a defined position, this piece of shape having a surface of negative profile

  compared to the superficial shape of the surface area

support.

  Each bracket clamp is provided with

  minus three probing surfaces, spaced one from the other

  and not arranged on a straight line, these surfaces can each be palpated correctly by the ball of palpa-, e

  of a measuring probe of a measuring device of

  coordinate and associated in a positive

  known relative relation with the supporting partial surface

of the clamp.

  The clamping jaw is held with the possibility of oscillation.

  Other features and advantages of the

  will be highlighted in the rest of the

  description, given by way of non-limiting example, with reference to the accompanying drawings in which: Figure 1 is a schematic sectional view of a deep drawing tool comprising a die and a blank holder;

  Figure 2 is a side elevational view of a sup-

  port for a clamp, and Figure 3 shows on a larger scale a detail

  of the clamping bracket of Figure 2.

  The schematic representation of an employment tool

  embossing of Figure 1 shows a lower die 3 provided with an application surface 6, against which a blank 5 is applied by its edge; the blank is clamped by the blank holder 4, pushed down with a defined force The blank holder 4 obviously has a negative shape with respect to the shape of the surface

  of application 6 Inside the blank holder 4 is dis-

  put the stamping punch 1 and the counter-tool

  pressure 2 is disposed below the blank 5 at the

  of the matrix Obviously also other confi-

  stamping tools are possible in corres-

  with the basic structure of the printing press.

  associated stamping In each case, however, it is provided externally in the stamping tool a die and a blank holder, which clamp the edge of the blank

  with a defined force To obtain a result of

  correct embossing or stamped part free of defects, it is quite essential that the application surface 6 of the matrix has a specific shape

  for the stamped part, this shape must be

empirically undermined.

  For this purpose, the device that will be described below is used. This device allows a simulation, and also a rapid modification, of the function of the matrix 3 and the blank holder 4. For this purpose, several supports are provided. which carry with the possibility of movement a clamping bracket 10 and which can be freely moved in translation and rotation on a base 7, being able to be fixed in any position thereon The length and the width of the base are respectively bigger

  that the largest sheet blank 5 to implement.

  In addition, the base is oriented horizontally and is arranged so that its upper surface is as smooth and flat as possible When, for a solid attachment of the support 8 on its foot 9, grooves in

  T have been machined in the base 7, these are judici-

  carefully closed by reloading in the areas

  not necessary so as to obtain a superior surface

  Instead of T-slots, we could also

  numerous threaded holes distributed in the form of a network in the base so that it

  position the base plates of the brackets on the base.

  Because the supports 8 are very stable and consequently heavy, they are provided, to facilitate their movement, of guide rollers 31, which are

  adjustable in height by means of an actuating mechanism

  32 and which can be retracted completely into the foot 9 of the support 8 so that, when the guide rollers 31 are retracted, the base plate of the support rests directly on the base 7 and that

  the support is fixed on the base only under the ac-

  its own weight by conjugation of forces.

  To increase the retaining force, the base plate as specified may be fixed on the base 7 using machined T-slots. In place of the retractable guide rollers, the support 8 may also be brought and fixed in position. desired angular position and

  control rollers that can be blocked This possibility

  may also be provided in addition to the possibility

  the descent of the guide rollers, constituting

  then a system of fixing beforehand in position.

  Each support carries a gripper clamp 10 which is mounted on the movable support with three degrees of freedom.

  tightening 10 can be adjusted and fixed in the upper

  tor along a vertical guide 13; in addition, the clamping bracket can be rotated, and fixed, around two

  mutually orthogonal pivot axes 11 and 12.

  In the exemplary embodiment shown, the vertical guide 13 is arranged in the form of a column guide, comprising two guide columns 16, vertical and oriented in parallel, and a carriage 17 guided on them. The carriage 17, guided vertically, of the support can be operated accurately and fixed automatically by means of a flywheel 19 and a fine-threaded spindle 18 In the carriage 17, provision is made

  an internal thread cooperating with the spindle

  end stage 18 whereas against this threaded spindle

  end 18 is mounted in a rotating fashion, but without

  axial translation unit, in the main crosspiece arranged at the top on the guide columns 16; the steering wheel 19 is mounted at the upper end of the spindle

with fine thread 18.

  The first of the two pivoting bearings of the clamping caliper 10 is constituted by a pair of guide sleeves 20, horizontal and arranged on

  the carriage 17, and by a guiding pin 21,

  The guiding pin 21 can rotate about the first axis 11 within the guide sleeves 20 for this purpose. In this embodiment, the embodiment shown in FIG. on the guide pin 21 and in an area between the two guide sleeves 20, a pair of lever arms 22 which are connected at their outer ends and by means of a pivot joint to a fine-threaded pin 23 On the carriage 17, there is provided above the two lever arms 22 a flywheel support 25 consisting of a

  pair of consoles arranged one above the other

  be; these two supports are traversed by the fine-threaded spindle 23 and a flywheel 24 is mounted between the two supports without the possibility of axial displacement but with the possibility of oscillation. The flywheel 24 is provided at the center of an internal thread that can be screwed onto the spindle with fine thread 23 By rotation

  of the flywheel 24, the guide pin 21 can be moved

  pivoted precisely because of the irreverence

  the fine threading and a certain difficulty in operating the steering wheel 24 within its axial support, the automatic fixing of the guide pin in the new angular position is obtained

take each time.

  At the end, directed towards the clamping bracket

  , of the guide pin 21, there is provided a joint

  pivoting section 26, pivotable unidimensionally

  and in which the clamping yoke is hinged to the guide pin 21 In the basic position, shown in FIG. 2, the guide pin 21 and the hinge 26, the second pivot axis 12, defined by the joint 26, is oriented horizontally In all c-as,

  the second pivot axis 12 is, however,

  to the first pivot axis 11 Also for a pivoting of the clamp 10 relative to

  to the guide pin 21 through the armature

  In particular, a further threaded spindle 27 is pivotably articulated to the guide pin 21, the hinge eye and the pin axis being spaced apart from the second pin. pivoting axis 12 In the embodiment shown, a forked steering wheel support 29 is disposed on the clamping bracket 10 and is traversed by the fine-threaded spindle 27. Between the branches of the forked bracket of the flywheel, it is also provided a flywheel 28 which can not move in axial translation but which can however oscillate and which carries in the center again an internal thread which can be screwed on the fine threaded spindle By means of this spindle drive mechanism, the clamping bracket 10 can be pivoted accurately around the second pivot axis

  12 and be stopped automatically thanks to the irreversibility

  viability of the screwdriving drive in the new

position found.

  The clamping clip 10 in the form of a clamp

  door, on the lower inner surface of the opening

  gripper surface, a partial bearing surface 14, which constitutes a partial zone of a bearing surface at

  simulate for the sheet blank 5 It is intended in the

  tweezers, opposite to the partial surface

  14, a clamping jaw 15, which is displaceable

  parallel to itself and which is guided in a direction perpendicular to the partial surface

  The clamping jaw 15 can be

  against the partial bearing surface 14 with a defined force For this purpose, it is provided in the upper part of the gripper clamp 10 in the form of clamp

  a hydraulic piston 30 whose stem ensures not only

  The clamping jaw 15 is mounted with the possibility of oscillation at the outer end of the piston rod, and during the closing movement, the clamping jaw 15 is mounted with a defined force. clamping jaw can

  easily adapt to the position of the edge of the blank.

  By simultaneous introduction of a high pressure fluid

  in the hydraulic piston 30, it is possible to simulate, in all the clamping brackets participating in the simulation, a clamping force corresponding to the conditions of use and thus to observe whether the sheet blank tight zone by zone on the The crimping clamp and the associated hydraulic piston 30 must be made with a sufficiently stable structure so that it is possible to produce with the crimping pliers.

  clamps also clamping forces

  lists of up to approximately

k N by clamping clamp.

  In order to be able to simulate with the clamping bracket not only partial bearing surfaces 14 which are plane but also curved surfaces,

  these are created on a piece of form 33,

  geable and can be set up in a position

  defined in the lower part of the clamp.

  By means of fixing pins 35, the shaped piece 33 is held in a defined position on the receiving surface of the clamping clamp. Correspondingly, on the opposite clamping jaw a shaped piece 34 can be placed. places in a defined position and which has a surface whose profile is negative relative to the profile of the partial bearing surface 14 With such sets

  exchangeable pieces of form 33 and 34, it is pos-

  sible to achieve, and to vary, during simula-

  all forms of partial support surfaces

who can intervene in practice.

  When, after several tests, which can be carried out quickly and without great expense, an exploitable "simulated" form of the bearing surface 6 has been found by means of the various clamps 10, the relative position of the clamping brackets between them

  is determined by means of a measuring device of several

  Coordinators, which has been installed in the area between the brackets and which was previously occupied by the blank 5 It is then necessary to remove the blank 5 of the brackets from the brackets and install instead between

  the supports a measuring device of several coordon-

  With regard to this measuring device of several

  In the case of co-ordinates, it is

  a single-stud type with a horizontally biased measuring arm However, it is possible to use a multi-coordinate measuring device of the portal type, which can be used instead.

  above the base 7 and the supports installed

  on it in the manner of a crane bracket and in which is mounted on a movable carriage, a measuring arm that can move up and down and at the lower end of which is disposed a probe

  36 When measuring the position of the

  To sort the tightening, it is not possible to determine the absolute position of the various clamps in the space and only their relative positions are determined. In order to be able to analyze the position found for the clamping brackets with a multi-coordinate measuring device, there is provided in each clamping bracket 10 at least three sensing surfaces 37 spaced from one another and which are not located on a unitary line but at the vertices of a triangle, preferably rectangle, or a polygon In the case

  o probing surfaces, each representing different

  points, are located at the vertices of a right triangle, it is advisable that the sides of the triangle are oriented parallel or perpendicular to the front side of the clamp and that the plane

  triangle is parallel to the partial surface of the ap-

  In the exemplary embodiment shown, the sur-

  probing faces were arranged as hollow cones, in which the probing ball of a probe

  of measurement 36 can go down and so the surface of pal-

  page 37 can be clearly palpated. By analyzing the spatial positions of at least three such probing surfaces 37, it is possible to clearly determine the spatial position of the clamping bracket 10. analysis is only possible by means of a determination of the absolute position of the different probing surfaces 37 with respect to a point of origin of the multi-coordinate measuring apparatus. However, after all the probing surfaces 37 of all the calipers have been analyzed, the position of the reference system in the measurement no longer plays any role and it is then possible to directly exploit the relative positions

  different points or different stirrups of

  between them and to represent them graphically on a graphical recorder. These data can be used for the construction of a matrix 3 or a

  corresponding blank holder 4 suitable for use.

  It could of course be envisaged, for easier setting up or removal of a sheet blank 5 in the clamping bracket 10, to arrange it

  with the possibility of folding For reasons of

  stability in case of a predetermined weight

  completed and as small as possible, however, it is

  wiser than the clamping bracket is intrinsically-

  rigid and immobile establishment or removal of

  of a blank in a ring of clamps are then made so that the brackets or clamps are spaced a distance laterally on one side of the ring and, after the introduction of the blank in the remaining clamping brackets, be brought back to a position which was previously marked on the base 7 by color markings The first experiments with this method showed that the previous position of the supports could be reproduced with precision

sufficient.

  In order to be able to control to what degree the blank edge clamping in accordance with the invention, or its spatial shape thus produced, was consistent with

  the blank form being established in a stamping tool

  deep-seated, the clamps have been adjusted in correspondence with the stamping profile of a stamped part already involved in mass production and the blank of the series part has been tightened in the state of coarse blocking of the edges that is to say before the downward movement of the punch -; this state was fixed in the blank by bristles produced on the edge,

  such that the custard does not change after opening.

  By tightening such a blank in the pre-set clamps, the state obtained in the series production can be defined with sufficient precision and the blank shape can be measured. the clamping brackets set in the same manner an untreated blank of the same part and also determined by measuring techniques the blank shape then establishing A comparison of the measured values showed an average deviation of position at maximum of 3 to 4 mm for points of the surface of the blanks to be compared, or their spatial shapes, which meant a very good match.

Claims (9)

  1 Device for an optimization, by simulation, of the application of a blank (5) of sheet metal against the matrix   of a stamping tool, characterized in that it comprises   takes the following components, having the particularities indicated in the following: a base (7) plane, oriented horizontally and whose length and width are respectively larger than those of the largest blank (5) to implement, several supports ( 8), freely movable on the base (7), rotatable about a vertical axis and can be fixed in any translation position or any angular position on the base (7), each support (8) having a clamping bracket Clamping device (10) which, by means of corresponding bearings, can be pivotally displaced and fixed around two horizontal and perpendicular axes of rotation (11, 12) and which can, by means of a vertical guide (13) which can be immobilized, be adjusted and fixed in height on the support (8), each clamping bracket (10) comprising: on the lower inner surface of the clamp opening, a partial bearing surface (14), which constitutes e a partial area of a bearing surface (6) to be simulated for the sheet blank (5), and facing the partial bearing surface (14) provided in the jaw opening a jaw   clamping device (15), movable in parallel and perpendicular   to the partial support surface (14) and can be applied with a defined force   against the partial bearing surface (14).   2 Device according to claim 1, characterized in that the vertical guide (13), adjustable and fixed in height, the support (8) is arranged as a guide provided with two guide columns (16), parallel and oriented vertically , as well as a cart (17) guided on them.   3 Device according to claim 2, characterized   in that, of the two bearings of the clamping bracket (10), which are horizontal and can pivot about two mutually orthogonal axes (11, 12), one of the bearings is constituted on the one hand by at least one guide sleeve (20), horizontal and arranged in or on the carriage (17), and secondly by a guide pin (21) extending rearwardly from the clamping bracket (10).   4 Device according to Claim 3, characterized   in that the other of the two horizontal levels is con-   staggered by a hinge (26), arranged between the -tou-   guide rail (21) and the clamp (10) and   able to rotate unidimensionally.   Device according to claim 1, characterized in that the actuating member is arranged as a hydraulic piston (30) for applying with a defined force the clamping jaw (15) of the clamp (10) against the surface partial support (14).   6 Device according to claim 1, characterized in that the support (8) freely movable on the base (7) and rotatable and also be fixed, is guided in its movement on the base (7) by means of guide rollers (31). ) that can be stopped and / or retracted completely. Device according to Claim 2, characterized   in that the carriage (17), guided vertically, of the sup-   port (8) is accurately movable by means of a flywheel (19) and a fine-threaded spindle (18) and   can be fixed automatically by irreversi-   bility of the fine-threaded spindle (18).   8 Device according to Claim 3, characterized   in that the guide pin (21) and / or the articu-   (26) of the clamping bracket (10) can be   by a flywheel (24, 28) and by means of a fine-threaded spindle (23, 27), supported for its pivoting movement, which is articulated by means of a lever ( 22) on the guide pin (21) or the clamp (10) and which is oriented   tangentially to the pivot axis cor-   respondent (11, 12), to be accurately moved and   be automatically fixed by means of irreversibility   the threaded spindle (23, 27).   9 Device according to claim 1, characterized   in that the partial bearing surface (14),   at the bottom in the gripper opening, is located on a shaped part (33) which can be exchangeably positioned and in a defined position in the lower part of the clamp (10) and that the clamping jaw (15) situated opposite the partial bearing surface (14) is also   provided with a piece of form (34), exchangeable and   to be installed on it in a defined position, this shaped piece having a profile surface   negative in relation to the superficial form of partial support face (14).   Apparatus according to claim 1, characterized   characterized in that each clamp (10) of the supports (8) is provided with at least three probing surfaces (37) spaced from each other and not arranged on a straight line, these surfaces each being correctly palpated by the probing ball of a   measurement (36) of a multi-coordinate measuring apparatus   data and being associated in a relative position   known with the partial bearing surface (14) of the sort of tightening (10).   11 Device according to claim 1, characterized   in that the clamping jaw (15) is maintained with possibility of oscillation.